Weft thread supply apparatus for gripper shuttle looms



Nov. 19, 1968 E. PFARRWALLER WEI-T THREAD SUPPLY APPARATUS FOR GRIPPER SHUTTLE LOOMS Fild Oct. 4. 1966 6 Sheets-Sheet l Inventor:

. Erwin Pfurrwcller BYQLMQM M, J ln z 01..

ATTOR N 5Y5,

Nov. 19, 1968 E. PFARRWALLER 3,411,548 I WEFT THREAD SUPPLY APPARATUS FOR GRI PPER SHUTTLE LOQMS e Sheefs-Sheet 2 Filed Oct. 4, 1966 an {i A .3 9w NN/ IMHHHHHIIHHHJJ \M 8 mm 38. .3 mm m R A K N. N\ o R mm K 1 bw Q \Fp mm 3 av R Q WNW Q m mm mm a. Q m a a t a Q .wm 3 NM m In ventor: Erwin Pforrwoller ATTORNEYS Nov. 19, 1968 E. PF'ARRWALLER Filed Oct. 4. 1966 6 Sheets-Sheet 5 Inventor.-

Erwin Pforrwoller ATTOR NEYS Nov. 19, 1968 E. PFARRWALLER 3,411,548

WEFT THREAD SUPPLY APPARATUS FOR GRIPPER SHUTTLE LOOMS I Filed Oct. 4, 1966 6 Sheets-Sheet 4 Inventor: Erwin Pforrwoller BYGW M,

ATTORNEYS E. PFARRWALLER Nov. 19, 1968 WEFT THREAD SUPPLY APPARATUS FOR GRIPPER SHUTTLE LObMS Filed Oct. 4. 1966 6 Sheets-Sheet 5 Inventor- Erwin Pforrwuller avg: 5;,

. ATTORNEYS.

Nov. 19, 1968 E. PFARRWALLER WEFT THREAD SUPPLY APPARATUS FOR GRIPPER SHUTTLE LOOMS Filed Oct. 4. 1966 6 Sheets-Sheet 6 ATTORNEYS United States Patent 0 3,411,548 WEFT THREAD SUPPLY APPARATUS FOR GRIPPER SHUTTLE LOOMS Erwin Pfarrwaller, Winterthur, Switzerland, assignor to Sulzer Brothers Limited, Winterthur, Switzerland, :1 Swiss company Continuation-impart of application Ser. No. 534,473, May 9, 1966. This application Oct. 4, 1966, Ser. No. 584,131 Claims priority, application Switzerland, June 25, 1965,

,946/65 12 Claims. (Cl. 139122) ABSTRACT OF THE DISCLOSURE There is disclosed an intermediate Weft thread storage device for looms in which the weft bobbin remains outside the shed, including a rotating flyer or thread guide having a hollow shaft through which the thread is passed to an arm on the flyer, and a drum supported on and rotatably with respect to that shaft. By rotation of the flyer the thread is wound onto the drum, at a portion thereof of conical shape sloping radially inward toward the free end of the drum. Weights or magnets are provided to hold the drum against rotation without interfering with pulling of the thread off the free end of the drum as the thread is picked through the shed of the loom.

This application is a continuation-in-part of my application for patent Ser. No. 534,473, filed May 9, 1966, and now abandoned.

The present invention relates to apparatus for weft thread supply in looms for weaving of the gripper shuttle type wherein the weft thread is pulled from a storage bobbin located outside the shed, and more particularly to such apparatus wherein there is provided in addition to a main storage spool or bobbin an intermediate weft thread supply and storage device to which the thread passes from the bobbin and from which it passes to the gripper shuttle, both the bobbin and the intermediate storage device being located outside the shed.

In one known form of gripper shuttle loom, the weft thread intermediate storage device comprises a rotating drum of reel onto which the thread is wound from a stationary eye and from which it is unwound in a direction substantially parallel with the axis of the reel for insertion into the shed by means of a suitable inserting device. The thread unwound in this manner rotates in an undesirable way. In particular, the thread may continue to be unwound from the drum even after the weft thread insertion has been completed, so that it becomes slack and can form loops or twists. The invention provides an intermediate storage device for the weft thread which is improved in this respect. According to the invention the intermediate storage device includes a substantially cylindrical body fixed against rotation and a thread feeding eye or flyer arm which rotates about this body to develop a number of turns or coils thereon. For introduction into the shed the thread is unwound from this cylindrical body, being pulled therefrom in a direction substantially parallel to the axis of this body so that it can be removed therefrom even though the body is fixed against rotation. Withdrawal of the thread is therefore efiected from a stationary cylindrical body or drum. As soon as the introduction has been completed, i.e. as soon as the pick has been completed, removal of thread from the cylindrical body ceases in view of the stationary nature thereof. The weft thread can therefore never become loose at this point in the loom and no loops or twists can form which might be subjected 3,411,548 Patented Nov. 19, 1968 to extra strain on the next pick and produce breakage of the thread.

The stationary cylindrical body is theoretically equivalent to a weft thread bobbin having constant diameter and hence unchanging resistance to thread pull-off. The resistance to pull-off of the intermediate storage device of the invention is however substantially smaller because the stationary cylindrical body may readily be provided with a smooth surface of metal or plastic material, for example, which can be polished if desired.

In one embodiment of the invention the cylindrical body is provided, at that end thereof onto which the weft thread is fed, with a conical enlargement disposed approximately in the plane defined by the rotating feeding eye. By means of this conical enlargement, the turns of thread successively wound on the body push each other in the direction of declining cross-section of the cone and onto the cylindrical portion of the body, and thence to- Ward the end from which the thread is pulled for introduction into the shed.

In one preferred embodiment of the invention the rotating feeding eye through which the thread passes to be wound onto the drum is supported on a wheel having spokes shaped as the blades of a blower or fan, so as to generate a current of air over the drum and thereby to keep it free of fibrous material coming from the weft thread or otherwise from the weaving operation. Such cleanliness is particularly important in embodiments of the invention employing automatic means to control the rate at which weft thread is wound onto the drum as a function of the quantity of thread stored on it.

In another embodiment of the invention a weft thread braking device is provided at or near the axial end of the drum oif which the thread is ,pulled for insertion into the shed. This braking device imposes a frictional drag on the thread as it is pulled off, thus further insuring at all phases of the picking operation against the development of undesired slack in the weft thread as it is pulled 01f the storage drum.

According to still another embodiment of the invention, the storage drum is provided, between the conical enlargement thereof onto which the thread is wound by the eye and the cylindrical portion of the drum, with a second conical portion of lesser cone angle than the first which merges at its large end with the small end of the first conical portion and which merges at its small end with the cylindrical part of the drum. The drum may also be provided with a radially projecting collar at or near the axial end thereof off which the thread is pulled for insertion into the shed of the loom.

The invention will now be further described in terms of a number of non-limitative exemplary embodiments of the invention and by reference to the accompanying drawings wherein:

FIG. 1 is a diagrammatic representation of a loom incorporating the weft thread storage apparatus of the present invention, the loom being seen from the cloth end;

FIG. 2 is a vertical section through a part of the loom of FIG. 1, the view being partly in elevation and partly in section, and particularly illustrating the intermediate weft thread supply and storage apparatus of the invention;

FIG. 2a is an axial section through a modified form of construction for the conical body 39 of FIG. 2;

FIG. 3 is a sectional view taken on the line IH--III of FIG. 2;

FIG. 4 is a view similar to that of FIG. 3 but illustrating a modified form of construction;

FIG. 5 is a view similar to that of FIG. 2 but illustrating an embodiment of the intermediate weft thread storage and supply apparatus of the invention in which the support for the rotating thread-winding eye takes the form of a wheel whose spokes constitute the blades of a centrifugal blower for generating a current of air over the thread storage drum;

FIG. 6 is a perspective view of a blower-type support for the thread-winding eye of the kind shown in FIG.

FIG. 7 is an axial sectional view taken on the line VIIVII of FIG. 6;

FIG. 8 is a fragmentary view similar to that of FIG. 2 but showing another embodiment of the invention including a weft thread brake associated with the storage drum;

FIG. 9 is a fragmentary view showing an axial position for the weft thread brake of FIG. 8 different from that of FIG. 8 and with consequently a different braking effect;

FIG. is a sectional view taken on the line X-X in FIG. 8;

FIG. 11 is a fragmentary view in side elevation of the apparatus seen in FIG. 10, the direction of viewing being indicated by the arrow XI in FIG. 10;

FIG. 12 is a diagrammatic representation of an embodiment of the invention in which the weft thread brake of FIGS. 8 to 11 is caused to vary its braking action cyclically during each pick; and

FIG. 13 is another view similar to that of FIG. 8 but showing a third embodiment of the invention.

The gripper shuttle loom of FIG. 1 comprises two frame members 1 and 2 suitably fastened together. Between them extends a cloth beam 3 for the cloth 4, a warp beam 21, and suitable means to effect controlled rotation of the warp thread and cloth beams so as to maintain the warp threads under proper tension. A main drive shaft for the loom is shown at 5. A drive motor is shown at 7 connecting to the main drive shaft 5 via a coupling device 6, which may include a brake. The elements 1, 6 and 7 may of course be provided at either side of the loom. In addition, the loom includes a reed 8 for beating up the weft thread 10 and heddles 9 for formation of the shed. Various other elements not shown are coupled to the shaft 5 to be driven thereby.

The weft thread 10 is withdrawn from a supply bobbin 11 disposed outside the shed and normally supported in stationary position. For each pick or weft thread insertion the weft thread is fastened to a gripper shuttle 12 which is propelled by a picking mechanism 13 through a shuttle race 14, the shuttle entering at the point 13a. The race comprises a multiplicity of guide teeth or fingers which penetrate between the warp threads.

A weft thread intermediate storage device generally indicated at 22 is disposed between the storage bobbin 11 and the picking station 13a. The intermediate storage device 22 will be further described hereinafter. The shuttle travels to a catcher indicated at 15. A separate selvage-forming device 16 is provided at each edge of the warps, near the mechanisms 13 and 15. These selvageforming devices serve to center the inserted weft thread, to clamp it, and to sever it on the picking side. Also associated with each of the devices 16 is a selvage-forming needle which inserts the free weft end into the folowing shed to form a selvage at the edge of the fabric.

The intermediate storage device 22 is supported by means of an arm 23 affixed to the loom frame. See FIG. 2. The device 22 includes a set of bearings generally indicated at 24 supported on the arm 23. The ball bearings proper are shown at 25. A hollow shaft 26 is supported by means of ball bearing races from the bearing support 24. At the left end of the shaft as seen in FIG. 2, there is provided a pulley 27 mounted to turn freely on the shaft 26. This pulley is driven by means of a belt 28 from the drive pulley 29 of a motor 31.

The pulley 27 has affixed thereto a clutch plate 32 which cooperates by means of a magnetic coupling with a disc 33 fixed on the shaft 26. The disc 33 includes electromagnets 34 which can be energized via brushes 35 in a circuit including a switching device 36. When the magnetic coupling is energized, rotation of the dlsc 32 is imparted to the shaft 26.

At the right end of the shaft 26 as seen in FIG. 2, there is provided an eye 37 and a bore 38 through which the weft thread 10 passes from the inside to the outside of shaft 26. This shaft has atfixed to its right end a hollow conical body 39 which functions as a flyer arm. At the outer edge of the latter is provided a thread feeding eye 41 through which the weft thread is passed.

The shaft 26 includes an extension 42 inside the hollow cone 39. A drum 44 is rotatably supported with respect to the shaft in this space via ball bearings 43. Whereas the shaft 26 with its end 42 rotates, the drum 44 is held stationary as will hereinafter be further explained.

At its left end as seen in FIG. 2, the drum 44 includes a conical enlargement 45 disposed substantially in the plane defined by the rotating eye 41, which plane is normally vertical.

The right end of the drum 44 as seen in FIG. 2 is disposed within a ring 46 affixed to the support arm 23 so as to leave an annular space 47 between the ring and the drum. The ring 46 supports two permanent magnets 48 as shown in FIG. 3. The cylinder 44 carries two armatures or keepers 49 which cooperate with the magnets 48. In this way the drum 44 is prevented from following the rotation of the elements 26, 39, 41 and 42.

The support arm 23 additionally carries a light source 51 whose beam 52 is obliquely incident on the drum 44. The reflected beam 53 impinges on a photocell 54 which is shielded from the source 51 by means of a mask 50. The photocell is connected by conductors 55 to the switching device 36. The source 51 and switching device are additionally connected via conductors'56 and 57 to a source of voltage 58.

Lastly, there is provided on the support 23 a thread tensioner or brake 62 operated periodically in synchronism with rotation of the main loom shaft 5 by means of a cam 61 which is coupled to that shaft by mechanism not shown.

The mode of operation is as follows: When the loom is in operation, the magnetic clutch comprising elements 32, 33 and 34 is energized. The motor 31 is also energized from a voltage source 30, and rotates. Hence the hollow shaft 26 rotates with its cone 39 at uniform speed. The weft thread 10 isfed from the bobbin 11 through an eye 63 and through a thread tensioner 64 into the hollow shaft 26. The thread emerges from the shaft at 38 to pass outside the cone 39 and then through the rotating eye 41 toward the axis of the shaft. By virtue of the rotation of the cone 39 and eye 41 with respect to the stationary drum 44, a number of turns of the weft thread are built up on the drum. The arrangement is such that the turn nearest the eye 41 is formed on the conical enlargement 45 of the drum. The drum has a polished surface so that the arriving coils cause those already wound to slip to the right in FIG. 2 and thus move onto the cylindrical portion of the drum. After a number of revolutions have been executed by the shaft, several such turns will build up on that cylindrical portion. By reason of the polished nature of the drum surface and because of the looseness with which the turns are wound, each turn will be shifted to the right by the turn to the left of it.

During weft thread insertion, the thread 10 is pulled off the stationary drum 44 toward the right, in FIG. 2, passing through the annular space 47. As may be seen from FIG. 2, no balloon of thread forms in the region 10a. The thread then passes through an eye 65 and thence to the periodically operated thread brake 62 which is advantageously opened, as indicated in FIG. 2, during the thread insertion or picking operation. Thereupon the thread passes through a stationary eye 66, over a thread tensioning lever 68 subjected to reciprocating motion as indicated by the arrow 67, and then through a stationary eye 69 to the gripper shuttle 12.

FIG. 2 shows the phase at which the shuttle 12 has just gripped the thread to begin entry into the shed 72 formed by the warp threads 71.

The average axial length 73 of the space occupied by the turns of thread on the drum 44, which axial length is so far as possible to be maintained constant, is desirably made of such size that the length of the thread wound up on the drum corresponds approximately to the width of the cloth, i.e. to the length of one pick. If the axial length 73 of the space occupied by the coils on the drum extends to the right so as to cover the point 74 at which the light beam 52 is reflected, the reflected beam 53 will be interrupted, reflection occurring at most in a diffuse manner from the thread on the drum. The photocell 54 and the switching device 36 are so adjusted that with this reduction of light incident on the photocell, the supply of current to the magnetic coupling 32, 33, 34 is interrupted. The hollow shaft 26 and cone 39 accordingly come to rest and the further accumulation of thread on the drum 44 is temporarily halted, whereas the elements 31, 29, 27 and 32 continue to rotate.

When after one or more additional picks or, according to the width of the cloth during the course of a subsequent pick, enough coils are withdrawn from the drum so as to uncover the spot 74 at which the light beam is incident on the drum, the photocell will again receive the reflected beam so that the magnetic coupling will be restored by operation of the photocell 54 and switching device 36. The cone 39 resumes rotation so that once more the weft thread is withdrawn from the bobbin 11 and wound up on the drum 44.

In the modified embodiment of FIG. 4, the drum 44 includes an eccentric mass 73' by means of which the drum 44 is caused to be unbalanced. The weight of the mass 73 hinders rotation of the drum 44 so as to make the ring 46, magnets 48 and armatures 49 unnecessary.

In another modification, a trough is provided, as indicated at 75 in FIG. 2a,. to support the thread between opening 37 and eye 41. This trough, if open, will face the direction of rotation of the shaft. Alternatively it may take the form of a tube 76 between the eyes 37 and 41. In still another modification a single tube is provided between the locations of the eyes 37 and 41, the cone 39 being dispensed with, a suitable counterweight to the tube being provided. In the example of FIG. 2, the cone itself provides rotational balance.

In still another embodiment the magnetic coupling is dispensed with, the discs 27 and 32 being aflixed to the hollow shaft 26. The switching device 36 then operates directly on the supply of current to the motor 31, the energization of the motor being interrupted when the supply of thread on the drum obscures the reflection point of the beam thereon. In such a construction the motor 31 is advantageously provided with a brake assuring that the .motor can be promptly stopped when too much thread accumulates on the drum.

Control of the rate of rotation of the eye 41, i.e., of the flyer arm, can be alternatively effected by making the rate of rotation of that eye and of the shaft 26 and cone 39 (if present as such) to vary continuously and inversely with the axial length 73 of the space occupied by the thread on the drum, this rate of rotation, moreover, being reduced to Zero for a specified maximum value of that axial length. When the axial length 73 declines," the rate of rotation of the elements 26, 39 and 41 will conversely increase. In place of the drum 44, it is possible to use a different but substantially cylindrically formed body which need not be truly cylindrical but with a plurality of axially extending bars disposed in a cylindrical array. The conical extension 45 can also be replaced with a flange if the yarn or thread slips so easily on the surface of the drum that the individual turns will readily slip to the right.

FIG. 5 illustrates an embodiment of the invention similar to that of FIG. 2, but in which the member 39 which supports the thread-winding eye 41 takes the form of a centrifugal blower, drawing air over the drum 44 so as to keep it clean of fibrous material, thread ends and the like. Whereas in FIG. 2 the member 39 presents to the end of shaft 26 adjacent the bobbin 11 a continuous substantially conical or other convex surface of revolution, in the embodiments of FIGS. 5 to 7 it comprises a hub 139 keyed or otherwise fastened to the shaft 26, a circular rim or flange through which the winding-eye or eyes 41 are formed, and a plurality of spokes 82 supporting the flange coaxially of the hub. The spokes 82 extend axially as well as radially of the axis of rotation of the shaft 26, as is clearly shown in FIG. 5, and are bounded by web-shaped faces 82a. Upon rotation of shaft 26 therefore, the air in the spaces between adjacent spokes is caused to rotate, and hence moves radially outward as well, as indicated at the arrow 96 in FIG. 5, as in a centrifugal blower. Particularly because of the axial extension of the spokes from the hub 139 toward the drum 44, the result is an air-pumping action which draws air axially over the drum, to'the left in FIG. 5, so that the accumulation of fibrous material on the drum is hindered or prevented. This is particularly of importance to the dependable operation of the circuit including the photocell 54 for control of rotation of the thread-Winding eye.

The cleaning action of the air stream generated by the fan or impeller-shaped eye-supporting member 39a is important also in embodiments of'the invention in which the photocell circuit for control of winding speed employs a light beam path passing through an aperture in the drum. Thus instead of locating the photocell to be illuminated by light reflected from the drum as is illustrated in FIG. 5, the drum may have a slot cut in its surface, e.g. along a direction skewed to the axis of the drum. The source 51 and photocell 53 may then be located both outside the drum but with the path between them passing through this slot. With such a construction when thread coils 73 are laid onto the part of the drum where this slot is located, the light path between the source and photocell will be broken and the consequent change in illumination of the photocell may be employed as a signal to slow down or interrupt the rotation of the shaft 26.

In such an embodiment it is obviously necessary to avoid obstruction of the slot in the drum by waste fibrous material, and the constructions for the rotating eye support 3911 illustrated in FIGS 5 to 7 are effective to this end.

FIGS. 6 and 7 illustrate a slightly modified form of air-pumping support for the thread-winding eye. 'In these figures, the support 39a has less concavity on the side thereof presented to the drum 44, so that the blades 82 are bounded substantially radially at the edges thereof facing the drum. Nevertheless, by virtue of the inclination to the axis of the edges 97 which bound the blades on the axial side thereof away from the drum, the construction is effective to draw air axially over the drum into'the apertures 81 between the blades and thence to expel it radially outward, as indicated by the arrow 96 in FIG. 6.

In FIG. 6-, reference character 92 identifies a radially extending rim or flange on the member 39a, through 'which the eye or eyes 41 are formed. The flange is axially bounded on the convex side of the member 39a by a radial surface 93. Reference character 94 identifies a vestigial portion of the conical surface, apertured at 81 to-leave the air-pumping spokes 82. The apertures 81 may be bounded axially adjacent the rim 92 by radially extending surfaces, as indicated at 95.

To prevent the thread 10 from catching on the spokes 82, the leading edges thereof on the side away from the drum may be curved slightly toward the drum 44, as indicated at 97a in FIG. 6.

Alternatively, the blades or spokes 82 may be shaped to have helicoid surfaces so that the eye support 39 will operate as an axial blower.

FIGS. 8 to 11 illustrate an embodiment of the invention having, adjacent the end of the drum or cylindrical body from which the weft is pulled during picking, a weft thread braking device including flexible elements such as brushes extending inwardly toward the drum on which the weft thread is wound, in order to brake or retard the pulling off of the weft thread. The weft thread braking device advantageously includes an annular member or ring, coaxially surrounding the drum and being like it without rotation, the flexible members for frictional engagement with the thread as pulled off of the drum being supported on this ring. With the help of this braking device the weft thread, which during picking is accelerated by means of shuttle and unwound from the drum, is suitably braked in its unwinding at the end of the picking operation, when the shuttle itself is slowed down and stopped by the catching mechanism of the loom. Hence, no more thread can be withdrawn from the drum storage body than is required for the pick, and the formation of loops and tangles in the weft thread is avoided.

The braking device has the further function of holding the thread under light tension during that portion of the picking operation in which the thread tensioner at the entrance to the shed is shifted crosswise of the shuttle path from its middle position to a first upper position while the shuttle, after being stopped immediately upon emerging from the shed, is restored a short distance to an exactly defined yarn release position which keeps the width of the selvage constant since the projecting yarn ends are of equal length when tucked into the next shed. The braking device has moreover the additional function of holding the weft thread under light tension when the device which successively presents the end of the weft thread to a shuttle for a new pick and the inserted weft thread to a shear for cutting 01f, restores in a direction away from the shed the cut end of the thread after such cut-off. During this last restoring motion after cut-off of the weft thread, the thread tensioner executes a further motion crosswise of the shuttle path and a small additional amount of weft thread will therefore be pulled off the cylindrical storage body, but the weft thread is then also held under light tension by means of the brake.

Desirably that portion of the substantially cylindrical thread storage body which is surrounded by the brake is conically shaped to be of diminishing diameter toward the shed. The brake is axially adjustable over this conical end of the drum and can be fastened in any desired position over this range of adjustment by axially shifting the brake relative to the drum, particularly with respect to the conical pull-off end thereof, the effectiveness of the brake can be varied to take into account the nature, strength and weight of the weft yarn employed and the dynamic forces determined thereby which occur during the pick.

There may be provided apparatus for producing an automatic reciprocating axial motion of the weft thread brake in synchronism with the picking operation so that at the beginning of each pick the brake is moved axially of the drum storage member to a position of relatively low braking effect whereas toward the end of the picking operation it will have been restored to a position of relatively large braking efiect. Thus in this embodiment the braking effect is automatically adjusted within each cycle of the loom and more particularly within the picking operation thereof.

Referring now to FIG. 8, it will be seen that this figure illustrates apparatus similar to that shown in FIG. 2, the drive to the shaft 26 and the photocell control of that drive having been omitted for simplicity. In FIG. 8 reference character 22 is applied with a bracket to identify so much of the apparatus there shown which constitutes an embodiment of the intermediate weft thread storage and supply apparatus shown diagrammatically by means of that reference character in FIG. 1.

In the embodiment of FIGS. 8 to 11, the drum 44 carries an eccentric weight so as to remain stationary, without partaking of the rotation of the shaft 26. The storage drum 44 includes a first conical extension or enlargement 45 at the end thereof adjacent the shaft 26 and a second conical portion of diminishing diameter at the opposite end thereof. The conical portion 80 is surrounded by means of a weft thread brake ring 83 which supports flexible elements such as bristles 84 which may be of nylon or of a natural thread fiber or the like. The bristles are made up into brush-like bundles and extend radially inwardly toward the axis 85 of the shaft 26. The bristles are held on the brake ring 83 by means of a wire 86 and may be cemented in place.

The ring 83 is supported coaxially of the drum body 44 by an arm 87 of the loom frame. More particularly, the ring 83 has two guide screws 88 afiixed thereto as shown in FIG. 10, threaded into the ring down to their shoulders 89. Additionally, a set screw 90 having a hand grip 91 is movably threaded into the ring. The ring 83 is supported for limited rotation about and limited translation along its own axis by means of an arcuate member 77 fastened to the supporting arm 87. The member 77 includes three oblique, helically extending slots 78 as illustrated in FIGS. 10 and 11 through which the screws 88 and 90 extend. When the set screw 90 is not tightened, the ring 83 can be circumferentially rotated, backwardly and forwardly, by motion of the hand grip 91 as indicated at the arrow 79. With this motion, the screws 88 and 90 move within the slots 78. FIG. 11 illustrates, for one of the screws 88, how rotation of the ring 83 about its axis, by shifting the screws 88 between the positions 88a and 8812 at the ends of their respective slots 78, will shift the ring 83 along its own axis through the distance S. The ring 83 can be made fast to the supporting member 77 anywhere in this range of positions by'tightening the set screw 90.

The median plane of the braking ring 83 can accordingly be shifted axially, either to the right or to the left in the views of FIGS. 8 and 11 over a distance indicated at S in FIG. 11. The ring can, for example, have the intermediate position shown in FIG. 8 in which the braking effect on the thread 10 is of an intermediate value, in consequence of the intermediate separation there existing radially of the axis 85 between the ring 83 and its brushes 84 on the one hand and the conical surface 80 on the other. FIG. 9, which corresponds to disposition of the screw 88 of FIG. 11 at the end 8812 of the slot 78 shown in FIG. 11, shows the axial position of the brake ring in which the braking effect will be strong because the radial distance between the ring and the conical portion 80 of the storage drum will be small, so that the brushes 84 will bear heavily against the drum and therefore against the weft thread as it is pulled off the drum between the drum and the brushes.

The mode of operation of the apparatus of FIG. 8 to 11 is as follows: During operation of the loom, rotation of the cone 39 continuously pulls weft thread from the bobbin 11 through the hollow shaft 26 and through the eye 41 formed on the cone or flyer arm 39, and the thread so withdrawn is wound onto the drum 44. During each pick the thread 10 is unwound from the drum 44 and inserted into the shed 72 formed by the warp threads 71, the insertion being effected by a shuttle 12. The thread passes from the right-hand end of the drum 44 through a stationary eye 66, through a thread tensioner 68 which is movable up and down as indicated at the arrow 67, through a further stationary eye 69 and through a thread feed and return device 96' which is horizontally movable as indicated by means of the arrow 96'. By means of this device 96, the end of the thread originating at the spool 11 is led to the shuttle 12 before the start of the pick. The thread is then gripped by a gripping device of the shuttle, whereupon the device 96' is opened to release the thread.

The weft thread is now picked into and through the shed. In the course of the flight of the shuttle several turns or coils 73 are pulled off of the storage drum 44. The shuttle then passes into the catcher 15 on the far side of the shed (cf. FIG. 1), not shown in FIG. 8, where it is slowed down by means of the braking ring 83 and its brushes 84 acting on the conical portion 80 of the drum 44. By virtue of the braking effected by the brushes the formation of loops and tangles in the weft thread is prevented in the region between the conical portion 80 of the drum and the eye 66, the thread being maintained always under slight tension there.

In the catcher the shuttle 12 is now restored backwardly from its stopping position to a yarn release position. At the same time, the device 96' of FIG. 8 is moved toward the right, toward the shed, but without gripping the thread, and the thread tensioner 68 is moved upwardly as indicated by the arrow 67 to a first upper position, thus keeping the weft thread taut notwithttanding the short backward motion of the shuttle. During this upward motion of the thread tensioner 68, a further length of thread will be drawn off the storage drum 44, and the brake member 83 and its brushes 84 keep the thread taut between the drum 44 and the tensioner 68.

At the end of the backward motion of the shuttle the weft thread will be grasped by the device 96, now in its right-hand position, .adjacent the shed. At that time, the weft thread is cut off by means of a shearing device not shown at a location between the device 96' and the shuttle. Thereupon the thread return device 96, holding the end of the thread leading to the spool 11, will be moved back to the left, during which motion the thread tensioner 68 will be further moved upwardly. This further motion of the tensioner will cause some additional thread to be drawn off the drum 44, in the course of which again the braking ring 83 prevents the formation of loops and tangles. The loom cycle thereupon begins again.

In the embodiment fragmentarily illustrated in FIG. 12, the axial motion of the brake ring 83, in accordance with the arrow 98 of FIG. 8, is caused to occur cyclically in synchronism with the operation of the loom, once for each pick. In FIG. 12 there is shown a shaft 105, which may be parallel to the shaft 26, and which is coupled to the main shaft 5 of the loom to make one revolution for each pick of the loom. Shaft 105 carries aifixed thereto a cam 106, whose follower 107 is spring-loaded against the cam. The follower moves in guides 108, and is coupled to a pin 91' fastened, like the pin 91 of FIG. 10, to the screw 90 described in connection with FIGS. 8 to 11. The cam 106 is so shaped and is so phased on the shaft 105 that at the beginning of the picking operation the brake ring 83 will be in the position of moderate braking shown for it in FIG. 8, or indeed in a position to the right of that shown in FIG. 8 so that the ring bears either only slightly or not at all on the weft thread 10 by means of its brushes 84. By the end of the picking operation the ring 83 will be moved by the cam 106 into the position shown for the ring in FIG. 9, in which the thread is more effectively braked.

In place of the brushes 84, the braking ring may be provided with flexible teeth of metal or rubber or of a synthetic material. Alternatively, there may be employed in place of the brushes 84 a strip or ring of felt having radial slits. Alternatively, instead of a complete ring or cylinder such as has been shown at 83 there may be employed a number of arcuate braking sections supported coaxially of the drum 44, which together cover something less than a complete circle. Two or three arcuate members of 90-extent may be so employed. Each of these is then provided with flexible elements such as the brushes 84, having inwardly radial extension to engage the surface of the drum 44.

FIG. 13 illustrates an embodiment of the invention in which the drum 44 includes, in addition to the conical enlargement 45 onto which the thread is wound by the rotary eye or fiyer arm, a second conical portion 101 tapering in the same direction, i.e. toward the shed, but of smaller cone angle than the portion 45 and inserted between the conical enlargement 45 and the cylindrical portion 102 of the drum, and also a ring or flange 103 projecting outwardly from the cylindrical portion of the drum at or adjacent the free end of the drum over which the thread is pulled by the shuttle into the shed. The second conical portion 101 may for example have a half-cone angle of 3 between the axis and the geometrical elements of the surface 101. The flange or ring 103 is advantageously made to have a maximum diameter greater than the diameter of the drum at the junction 104 between the conical parts 45 and 101.

This shape for the surface on the intermediate thread storage member 44 has proved particularly advantageous. The weft yarn runs under tension from the eye 41 onto the first conical portion 45 and slides thereover in the direction of the second, less steeply conical portion 101 because of the conical shape of the first portion and because of the smooth surface which is desirably imparted thereto. Newly wound coils push along, in the direction of taper, coils already wound on so that the Weft thread or yarn is relieved of tension when it arrives on the portion 101. The cylindrical portion 102 that follows is of axial length adequate to store a length of yarn suflicient for one pick, according to the width of the cloth to be woven. The length so stored is preferably a little longer than the cloth width. Finally, the flange 103 at the free end of the storage drum 44 prevents coils of yarn from slipping off the drum. The flange 103 is surrounded by a weft thread braking ring 83 which is supported, preferably in an adjustable manner as described in connection with FIGS. 8 to 11, on a fixed supporting element 87 of the loom so as to be adjustable axially of the drum 44 as indicated by the arrow 98. The braking ring 83 carries brushes 84 or equivalent flexible braking elements as described in connection with FIGS. 8 to 11. When the brake ring is arranged for axial shift, as in the embodiment of FIGS. 8 to 11 or of FIG. 12, the flange 103 desirably has a conical shape at its radially outer surface, as indicated at 111, to cooperate with the axially shiftable brake ring.

It will be appreciated from the foregoing that even beside the intentional departures from cylindrical shape for the storage drum 44 shown at the conical enlargement 45 in FIG. 2, or at 45 and at 101 and 103 in FIG. 13, the invention is not limited to the use of a truly cylindrical body for the intermediate storage of the weft thread, and the expression cylindrical body is to be understood as including any suitable device such as a plurality of bars supported about an axis in the position of elements of the surface of the cylindrical body 44 of any of FIGS. 2, 5, 8 and 13. It will similarly be appreciated that the inverse variation provided, in the embodiments of FIGS. 2 and 5 between the rate of winding of thread onto the cylindrical body and the axial length of the space occupied by the'turns of thread on the body need not be a continuous one. A fortiori it need not be, in any range, an inversely proportional one. On the contrary it is preferably discontinuous, accumulation being stopped when that axial length reaches a maximum allowable value and being restarted when that axial length falls below that maximum.

While it has been stated hereinabove that the average axial length of the space occupied by the turns of weft thread or yarn on the drum 44 is maintained so far as possible constant, it is to be understood that the length of thread on the drum will vary over the loom cycle. Thus, while the shuttle passes from the picking side of the loom to the catching side thereof, thread will be removed from the drum faster than it is supplied thereto, while during the remainder of the loom cycle thread will be supplied to the drum faster than it is removed therefrom.

While the invention has been described hereinabove in terms of a number of presently preferred embodiments,

all modifications of and departures from those embodiments falling within the spirit and scope of the appended claims.

I claim:

1. Intermediate weft thread storage apparatus for use in a loom having means to form warp threads into a shed, a weft thread bobbin outside the shed, and means to pull the end of a weft thread through the shed, said apparatus comprising a hollow rotatable shaft, a bearing supporting the shaft for rotation, at substantially cylindrical body, means supporting said body from one end of said shaft for rotation with respect to said shaft about the axis of rotation of said shaft, a flyer arm affixed to said shaft and extending radially and axially thereof into exterior overlapping relation with the surface of said body, and means restraining said body against rotation whereby a weft thread passed through said shaft and out onto said arm will be wound up on said body upon rotation of said shaft, and whereby said weft thread may be pulled off the end of said body remote from said flyer arm.

2. Apparatus according to claim 1 wherein said body includes a radial outwardly extending flange at a position adjacent the end thereof remote from said shaft.

3. Apparatus according to claim 1 wherein the surface of said body includes a conical portion aligned with said flyer arm.

4. Apparatus according to claim 1 wherein the axis of said shaft is substantially horizontal and wherein said restraining means comprise a mass disposed on said body eccentrically of said axis.

5. Apparatus according to claim 1 wherein said restraining means comprise two-part magnetic means of which one part is mounted stationarily with respect to said bearing and of which the other part is mounted on said body.

6. Apparatus according to claim 1 including means affixed to said shaft to circulate air over said body upon rotation of said shaft.

7. Apparatus according to claim 1 further including flexible means bearing against a portion of the surface of said body at a position axially of said body toward the end thereof remote from said shaft.

8. Apparatus according to claim 7 wherein said portion of said surface is of decreasing radius toward the end of said body remote from said shaft.

9. Apparatus according to claim 8 including means to adjust the relative position of said body and flexible means axially of said body.

10. Apparatus according to claim 8 including means to alter cyclically the relative position of said body and flexible means axially of said body.

11. Apparatus according to claim 8 wherein said position-altering means include an arcuate member supported substantially coaxially of said body, said arcuate member having a plurality of substantially helical slots therein, an annular member supporting said flexible means, and a plurality of pins mounted on said annular member and engaging each one of said slots.

12. Apparatus according to claim 1 wherein the surface of said body includes a first conical portion aligned with the end of said flyer arm, said first conical portion tapering toward the end of said body remote from said flyer arm, and wherein the surface of said body includes a second conical portion of lesser cone angle than said first conical portion disposed between said first conical portion and the end of said body remote from said flyer arm, said second conical portion tapering toward the end of said body remote from said flyer arm.

References Cited UNITED STATES PATENTS 1,187,827 6/1916 Gibbs 24282 2,662,556 12/1953 Svaty 139127 2,716,007 8/1955 Scott 24282 2,749,946 6/1956 Pfarrwaller 139126 3,093,339 6/1963 Godderige 24282 3,204,940 9/1965 Morgan 24282 X 3,225,446 12/1965 Sarfati et al. 24247.12 X 3,263,705 8/1966 Rossmann 139224 X 3,276,484 10/1966 Bucher 139122 3,280,853 10/1966 Brown et al. 139122 FOREIGN PATENTS 966,563 8/1957 Germany. 1,335,638 7/1963 France.

MERVIN STEIN, Primary Examiner.

J. KEE CHI, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 1 3 411 54 DATED 1 November 19 1968 INVENTORtS) E Pfarrwaller It is certified that error appears in the above-Identrtied patent and that said Letters Patent are hereby corrected as shown below;

In the masthead of the patent, after "Claims priority, application Switzerland, June 25, 1965, 8,946/65", insert -application Switzerland, October 5, 1965, 13,748/65; application Switzerland, October 5, 1965, 13, 749/ 5; and application Switzerland, October 6, 1965, l3,752/65.-

Signed and Scaled this Arresr:

RUTH C. MASON .-1Ilrs!r'rrg Officer C. MARSHALL DANN (runmim'um'r uflan'nls and Trademarks 

